PROJECT SUMMARY/ABSTRACT A breakthrough lightweight, compact 3T MR scanner has been demonstrated to have gradient performance of 700 T/m/s slew rate, operating at 80 mT/m amplitude), which is a slew rate that is 3.5x faster than whole-body MRIs. The proposed next phase of the program will deliver key neuroimaging tools through a multi-disciplinary collaboration between Mayo Clinic and GE Global Research. This proposed work includes further technical development in image reconstruction, systems artifact correction, and pulse sequence programming that exploits the unique, high-performance capabilities of the compact 3T. The Specific Aims of the project are to: Aim 1) Develop Core Technologies for Echo Planar Imaging (EPI) on the Compact 3T Aim 2) Develop New MRI-based Connectomics Aim 3) Develop High-Resolution MR Elastography (MRE) Brain Stiffness Measurement Aim 1 focuses on improving EPI on the compact 3T system to maximally capitalize on its unique gradient slew rate and specific absorption rate (SAR) advantages. Specific tasks related to this aim include: the development of model-based reconstructions, real-time system compensation to eliminate concomitant field artifacts, pulse sequence development for segmented EPI for very fast anatomical imaging, and improved efficiency for simultaneous multislice (SMS) by exploiting the SAR advantages. Aim 2 exploits the compact 3T's dramatically reduced susceptibility artifacts in the region of the medial temporal lobe to enable task-free fMRI spontaneous coactiviation studies of the entire brain, including the hippocampus, which is central to the study of Alzheimer's disease (AD). Aim 3 describes how the compact 3T's high-performance gradients enable, for the first time, 3D gradient echo-based MR elastography (3DMRE). This will enable an 8x reduction in the acquired voxel size compared with the 2DMRE currently acquired with our whole-body MRIs. This has important applications, not-only to pre-surgical planning for tumor resection, but also to potentially develop new biomarkers for the study of neurodenegerative disease, such as AD. The new 3DMRE technique will be studied in the same patient cohort as Aim 2. We believe vastly improved spatial resolution and scan efficiency on the compact 3T MR platform will enable new clinical and neuroscience applications for assessing brain disease management, including traumatic brain injury, tumor treatment planning, and neurodegenerative diseases.